1. Field of the Invention
The present invention relates to a fuel cell and cell fastening pins for fastening elements of a unit cell which is a constituent of the fuel cell.
Priority is claimed on Japanese Patent Application No. 2004-338974, filed Nov. 24, 2004, the content of which is incorporated herein by reference.
2. Description of the Related Art
In a known fuel cell, an anode and a cathode are provided on either side of a solid polymer electrolyte membrane so as to form a membrane electrode assembly. The membrane electrode assembly is placed between separators which are provided so as to form a unit cell. Generally, a specific number of unit cells are stacked to form a fuel cell stack.
In consideration of easy handling, working convenience, productivity, or the like for the above kind of fuel cell, in each unit cell, the membrane electrode assembly and the separators on either side thereof may be fastened together so as to prevent separation of each element of the unit cell.
For example, Japanese Unexamined Patent Application, First Publication No. 2004-241208 discloses a technique in which a plurality of parts in a periphery of each unit cell are clipped together using elastic metal clips having a U-shaped section.
However, in the above case of fastening and forming a unit cell using the elastic clips, each elastic clip must be attached to the periphery of the unit cell while opening the mouth of the clip in opposition to an elastic force, which requires a special jig or tool. Therefore, this process is inconvenient and requires an additional cost, thereby increasing the manufacturing cost.
In addition, weight saving of elastic metal clips has a limit. In particular, when tens to hundreds of unit cells are stacked so as to form a fuel cell stack, the total weight of the elastic clips is large, which prevents weight saving of the fuel cell stack.